<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>2021-10-14-a</title>
</head>

<body>
    <script>
        // 判断  if else  else if else
        var sco = 80;
        //大于80 优秀
        //大于60及格
        //小于60不及格
        if (sco >= 80) {
            console.log("优秀");
        } else if (sc0 >= 60) {
            console.log("及格");
        } else {
            console.log("不及格");
        }
        //三元运算
        console.log(sco >= 60 ? "及格" : "不及格");
        // switch case
        var day = 0;
        switch (day) {
            case 0:
                console.log("星期天");
                break;
            case 1:
                console.log("星期一");
                break;
            case 2:
                console.log("星期二");
                break;
            default:
                break;
        }
    </script>
</body>

</html>